9 - Active Structural Acoustic Control. II Cylinder systems

Abstract

This chapter focuses on the application of active structural acoustic control (ASAC) to sound transmission through, and radiation from, cylindrical structures. Such systems are representative of many applications. The control of sound transmission into aircraft is important, and in the low frequency region the fuselage can be adequately modelled as a cylinder. Piping systems are common in many applications and often carry unwanted vibrations and radiate noise. Submarine hulls can also be approximated as cylinders and active control is significant for the reduction of low frequency structurally radiated sound. The chapter provides information to the ASAC applied to various cylindrical structural systems which can be considered to form the basis of the above applications. The radiation of sound from cylindrical structures occurs in many important applications. Several examples are the radiation of sound from submarine hulls, break out of sound from circular air conditioning ducts and radiation of noise from piping systems. The chapter also presents infinite cylinders for modelling the system of interest. In some applications it is more representative to model the structural and acoustic systems using a finite shell and enclosed volume.